Submitted to: Journal of Environmental Quality
Publication Type: Peer reviewed journal
Publication Acceptance Date: 1/26/2006
Publication Date: 5/31/2006
Citation: Gao, S., Trout, T.J. 2006. Using surface water applications to reduce 1,3-dichloropropene emission from soil fumigation.. Journal of Environmental Quality, 35:1040-1048. Interpretive Summary: Methyl bromide (MeBr) is being phased out internationally as a stratospheric ozone depleting compound. Minimizing emissions of alternative fumigants to MeBr is critical to protecting workers, bystanders, and the environment, and to maintaining practical use of alternative fumigants for production of high value crops. This research tested the effects of surface water applications on reducing emissions of 1,3-dichloropropene (1,3-D) in soil columns and compared with plastic tarp treatments. Results show that surface water applications were as effective as or even more than using standard plastic tarp and at the same time, did not reduce 1,3-D concentrations in soil, indicating no tendency to reduce its efficacy for soil pest control. As using water is less expensive than plastic, surface water application practices show high potential to reduce fumigant emissions in field conditions, especially in areas where irrigation water and sprinkler systems are available.
Technical Abstract: Reducing emissions is critical to minimize the risk of detrimental impact of fumigation on workers, bystanders, and the environment and to continue availability of alternative fumigants to methyl bromide. The objective of this study was to determine the potential of using water applied to the soil surface to reduce fumigant emissions. 1,3-dichloropropene (1,3-D) was applied to soil (Hanford sandy loam) in columns. Treatments included control (dry soil with no surface water application and no plastic tarp), initial water application (16 mm water just before fumigant application) with or without standard high density polyethylene (HDPE) tarp, intermittent water applications (2.6 mm water at 12 and 24 h following the initial water application) without tarps, and dry soil with plastic tarps [HDPE and virtually impermeable film (VIF)] without water applications. Emissions and distribution of 1,3-D in soil gaseous phase were monitored for up to two weeks. Water applications were more effective in reducing emissions for a short period of time after water application than overall emission reduction. Cumulative 1,3-D emissions for the first 48 h were reduced 25% and 49% with initial water application and the two intermittent water applications post treatment, respectively and these reductions were 9 and 19%, respectively for the whole 2-week period. This study shows that using surface water application to reduce 1,3-D emissions can be comparable to or more effective than using HDPE tarp alone (13% emission reduction) although much less than VIF tarp (up to 90% emission reduction). Fumigant concentrations in soil gas phase were not reduced with the amount of water applied in this study, which indicates that fumigation efficacy should not be affected. The results indicate that more frequent surface water applications can maximize emission reduction for this soil.